(11x+55)(7x-55)=0

Solution for (11x+55)(7x-55)=0 equation:

(11x+55)(7x-55)=0

We multiply parentheses ..

(+77x^2-605x+385x-3025)=0

We get rid of parentheses

77x^2-605x+385x-3025=0

We add all the numbers together, and all the variables

77x^2-220x-3025=0

a = 77; b = -220; c = -3025;
Δ = b2-4ac
Δ = -2202-4·77·(-3025)
Δ = 980100
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{980100}=990$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-220)-990}{2*77}=\frac{-770}{154}
=-5
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-220)+990}{2*77}=\frac{1210}{154}
=7+6/7
$